Chen et al. (2025) How Do the Asian Highlands Affect Phase-Preferred Rossby Waves and Synchronous Heat Extremes in the Midlatitudes?

⚠️ Warning: This summary was generated from the abstract only, as the full text was not available.

Identification

• Journal: Journal of Climate
• Year: 2025
• Date: 2025-12-12
• Authors: Huayu Chen, Yimin Liu, Jilan Jiang, Tao Zhu, Bian He, Sheng Chen, W. Yao
• DOI: 10.1175/jcli-d-24-0674.1

Research Groups

This study investigates the influence of the Asian Highlands (AH) on quasi-stationary Rossby waves (QSWs) and synchronous heat extremes using climate model simulations. It finds that AH removal weakens QSW phase preference and shifts low-wavenumber phases, with complex network analysis revealing contrasting impacts on interregional heat extreme synchronization depending on the nature of AH removal.

Objective

• To investigate the influence of the Asian Highlands (AH) on quasi-stationary Rossby waves (QSWs) and related synchronous heat extremes.

Study Configuration

• Spatial Scale: Mid-latitudes, encompassing Europe, central Eurasia, East Asia, and North America.
• Temporal Scale: Analysis of weekly events and synchronous heat extremes within a climate model simulation context.

Methodology and Data

• Models used: Climate model simulations (specific model not named).
• Data sources: Output from climate model simulations.

Main Results

• Removal of the Asian Highlands (AH) or its thermal forcing slightly weakens, but does not eliminate, the phase preference of quasi-stationary Rossby waves (QSWs).
• The preferred phase of low-wavenumber waves (3, 4, and 5) shifts significantly upon AH removal, while higher-wavenumber waves (6, 7, and 8) maintain stable preferred phases.
• Significant surface air temperature maxima co-occur with upper-level anticyclones during weeks dominated by high-amplitude wave 5 or wave 6.
• Temperature maxima associated with wave 5 are zonally displaced when the AH or its thermal forcing is removed, consistent with the wave-5 phase shift.
• Temperature maxima linked to wave 6 remain largely unchanged despite AH removal.
• Removing the AH strengthens interregional synchronization of synchronous heat extremes across midlatitude regions, whereas removing only its thermal forcing weakens this synchronization.
• These contrasting synchronization responses are linked to changes in the zonal uniformity of the wave-6 envelope.

Contributions

• Provides new insights into the causal role of the Asian Highlands (AH) in modulating quasi-stationary Rossby waves (QSWs) and their influence on midlatitude extreme weather patterns, particularly synchronous heat extremes.
• Clarifies the differential impact of AH's topographic versus thermal forcing on QSW phase preference and interregional synchronization of heat extremes.

Funding

Citation

@article{Chen2025How,
  author = {Chen, Huayu and Liu, Yimin and Jiang, Jilan and Zhu, Tao and He, Bian and Chen, Sheng and Yao, W.},
  title = {How Do the Asian Highlands Affect Phase-Preferred Rossby Waves and Synchronous Heat Extremes in the Midlatitudes?},
  journal = {Journal of Climate},
  year = {2025},
  doi = {10.1175/jcli-d-24-0674.1},
  url = {https://doi.org/10.1175/jcli-d-24-0674.1}
}